The prospect of a nuclear war between the United States and Russia occurring within the next 10 years is low but not nonexistent.

The war in Ukraine is the dominant concern here. Russia views Ukraine as the detached limb of an imperium that was wrongly allowed to fade away with the end of the Cold War. Vladimir Putin views success in Ukraine not simply as a linchpin of his ambition to become a 21st-century version of Peter the Great but as a test of his viability as Russian president. Putin fears that the hundreds of thousands of Russian soldiers who have been killed or maimed in Ukraine, the heavy economic costs suffered as a result of the war, and the drain on Russia’s global prestige will be intolerable to Russians, including security elites, unless Putin can credibly claim victory.